Chemistry Reference
In-Depth Information
Br
S
Br
O
S
O
KI
O
O
S
O
Br
S
Br
56
O
1.
Li
55
2. SnCl
2
1. NaBH
4
2. SnCl
2
S
S
S
S
57
58
Fig. 27 Synthesis of thioaryl substituted heptacenes 57 and 58 [
58
]
was demonstrated. The optical band gap of 58 was determined to be 1.37 eV
(onset,
λ
max
¼
850 nm) [
58
].
4 Octacene and Nonacene
4.1 Parent Octacene and Nonacene
Larger acenes than heptacene have not been reported in the twentieth century.
There have been attempts to synthesize these, e.g., by the group of Orville Chapman
at UCLA, but these efforts have not met with success [
47
].
In view of the problems associated with the high reactivity of heptacene, it is
likely that parent octacene and nonacene are too reactive to be isolated in
